Female retirees saw their income rise by £450, and male retirees by £650. Both genders now expect an annual retirement income of £15,800 including income from private, company and state pensions.

This is £500 higher than in 2013 and the first rise in three years.

Vince Smith-Hughes, retirement income expert at Prudential, said he thought growing families could be the predominant factor behind the increasing gap, with women taking out an increasing length of time to have children.

He added: 'It is welcome news that average expected retirement incomes have increased for both men and women, but concerning that the gender gap remains stubbornly wide.

'The changes to pensions and how people can take their retirement income announced in the Budget last month will provide savers and retirees with more choices. However they don’t alter the fundamental fact that many people are not saving enough for a comfortable retirement.

'There are also some specific practical steps that women can take today to improve their retirement incomes in the future. These include maintaining pension contributions where possible during career breaks and making voluntary additional National Insurance contributions when returning to work.

'A consultation with a financial adviser or retirement specialist could help women put together an action plan to help increase their potential retirement income.’

The gender pay gap is at its highest since 2010, according to Prudential (Source: Prudential)

He added that he fears the retirement income gap could continue to widen as the gender pay gap continues to grow.

Just 41 per cent of women planning to retire this year feel financial well-prepared, the Prudential study found, compared with 54 per cent of men.

Just 29 per cent of women believe they will have enough income to enjoy a comfortable retirement compared with 47 per cent of men.

The gender gap is widest in London, where the average expected retirement income for women is £10,500 – just 43 per cent of the £24,500 expected by men.

The gender gap is the greatest in London, the survey found (Source: Prudential)

Women’s expected retirement income is lowest overall in the South West, at £9,650 a year.

Another recent study from LV= found a fifth of women within five years of retirement have no private pension savings and will rely solely on the state pension.

Meanwhile 30 per cent of women over 50 expect to work longer than they had previously anticipated.